1. Field of the Invention
The present invention relates to the field of electrical connectors. More particularly, the present invention relates to a cross connect terminal block applied in a telecommunication system for providing the connection from TIPs and RINGs wire sets (for transmitting wiring signals) of the central office to wire sets in distributed wires. The cross connect terminal block of the present invention can further include one or two sets of wiring plugs at the same time, and can optionally include an electrical protection means, so as to provide the connected wire sets with the protection against over voltage or over current, such as lightning strikes.
2. Description of the Prior Art
Cross connect terminal blocks are conventional, and have been applied in telecommunication systems as terminal blocks of a wire extending from the central office, such that the wire is matched and connected with a wire of user terminals. When a cross connect terminal block is used, the large-scale cable extending from the central office is usually one terminal thereof, and several small-scale cables tapped out from the cross connect terminal block are connected to other cross connect terminal blocks arranged in parallel, such that the wire sets of the cables in the central office may be connected to the wire sets of user terminals correctly. The cross connect terminal blocks allow the switch of telephone lines and tests on the lines, and realize the transmission of signals. To some arrangement modes, the cross connect terminal blocks also allow additional telephone lines to be connected to original lines.
Some patents on cross connect terminal blocks have been disclosed already. For example, U.S. Pat. No. 4,210,378 uses screws as fixing posts to realize connection of different pairs of wires, and the connection with the module is permanent in this invention, so the change for the wires is difficult. Prior arts that eliminate this defect and realize rapid and convenient connection include U.S. Pat. No. 4,431,247 and U.S. Pat. No. 4,815,988, and other different types of cross connect terminal blocks are available in U.S. Pat. No. 4,279,460 and U.S. Pat. No. 4,789,354. In theses prior arts, wire sets from a signal wire can easily be added to wire sets in the neighboring cross connect block through wires between contact elements of two blocks.
In addition to the content about the cross connect systems and cross connect terminal blocks disclosed in the prior arts, patents on connectors having insulative layers removed, such as U.S. Pat. Nos. 4,341,430 and 4,533,196, and GB Patent No. 2,129,630, have disclosed various types of telecommunication or electrical connectors. In these patents, wires are introduced into a U-shaped slot of a metal contact element, and the U-shaped element is used to remove the insulative layer of the wires, such that the conductor in the wires is pressed with an elastic force, and thus is electrically connected with the contact element. U.S. Pat. No. 4,127,312 and U.S. Pat. No. 5,147,218 have disclosed the methods that use the connectors with contact elements to remove the insulative layers for connecting the bare wires so as to realize connection of different sets of wires. U.S. Pat. No. 4,127,312 has described two end portions of each contact that are arranged at an angle of 90 degrees and are used differently. First, the portion of a contact with the insulative layer removed is used to enable the contact to be connected to the bare wires, and the opposite side of the contact has a tuning fork contact for connecting a branch portion of the contact in another connector, such that two contact elements are electrically connected. This patent has also described the method of forming this type of contacts.
Moreover, in addition to the common connection between a wire set and another wire set, U.S. Pat. No. 5,281,163 has also disclosed that wires are tapped out from the other side of a connected cross connect terminal block for other purposes, such as half tapping or test circuits. Thus, the half tapping or bridging of the circuit can be realized without interfering the continuity of the original circuit. U.S. Pat. No. 5,281,163 uses a terminal block for connecting a first set of wires and a plug for connecting a second set of wires, and inserts the plug into the terminal block to fix them, such that the normal cross connection mode is realized. Furthermore, the plug can be stacked for half tapping or testing the connection of the wire sets from the central office.
However, U.S. Pat. No. 5,281,163 is still a complicated method of connection, which has to use a fixed terminal block to connect the first set of wires, then use a plug to connect the second set of wires, and then insert the plug into the terminal block to realize the cross connection of the wire sets. Thus, more elements are required, and the operating procedure is complicated. To reduce the cost and to make the operators' work easier while maintaining the same advantages, the present invention is developed, which provides the normal cross connection function of the first set of wires and the second set of wires, and provides the half tapping or bridging of the circuit without interfering or interrupting the original loops.